Air dampers which provide low leakage are known in the art. In certain applications, a room, area or facility may require the ability to be isolated relative to the ventilation system of the building to contain chemical, biological or radiological hazards. Research laboratories, pharmaceutical production areas and chemical plants are examples where isolation is important. It is also important to provide adequate air ventilation to these facilities. If a hazardous material is spilled it becomes necessary to isolate the area of the spill. Air dampers with mechanical seals may be closed to help contain the air borne hazardous materials. However, over time the seals may become dirty or worn and lose their effectiveness, or the dampers may be damaged, bent, or obstructed by a foreign object preventing the dampers from fully closing. Further, failure of an air damper to provide the necessary isolation when required likely would only be discovered after a hazardous material is released.